Influence of dissolved organic matter and inorganic nutrients on the biofilm bacterial community on artificial substrates in a northeastern Ohio, USA, stream

2006 ◽  
Vol 52 (6) ◽  
pp. 540-549 ◽  
Author(s):  
Ola A Olapade ◽  
Laura G Leff
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Nutrient Dynamics ◽  
Inorganic Nutrients ◽  
Artificial Substrates ◽  
Response Patterns ◽  
Ceramic Tiles ◽  
Phylogenetic Groups ◽  
Leaf Leachate ◽  
The Individual

Stream bacteria may be influenced by the composition and availability of dissolved organic matter (DOM) and inorganic nutrients, but knowledge about how individual phylogenetic groups in biofilm are affected is still limited. In this study, the influence of DOM and inorganic nutrients on stream biofilm bacteria was examined. Biofilms were developed on artificial substrates (unglazed ceramic tiles) for 21 days in a northeastern Ohio (USA) stream for five consecutive seasons. Then, the developed biofilm assemblages were exposed, in the laboratory, to DOM (glucose, leaf leachate, and algal exudates) and inorganic nutrients (nitrate, phosphate, and nitrate and phosphate in combination) amendments for 6 days. Bacterial numbers in the biofilms were generally higher in response to the DOM treatments than to the inorganic nutrient treatments. There were also apparent seasonal variations in the response patterns of the individual bacterial taxa to the nutrient treatments; an indication that limiting resources to bacteria in stream biofilms may change over time. Overall, in contrast to the other treatments, bacterial abundance was generally highest in response to the low-molecular-weight DOM (i.e., glucose) treatment. These results further suggest that there are interactions among the different bacterial groups in biofilms that are impacted by the associated nutrient dynamics among seasons in stream ecosystems.Key words: biofilms, nutrients, DOM, bacteria, in situ hybridization.

scholarly journals Seasonal Response of Stream Biofilm Communities to Dissolved Organic Matter and Nutrient Enrichments

2005 ◽  
Vol 71 (5) ◽  
pp. 2278-2287 ◽  
Author(s):  
Ola A. Olapade ◽  
Laura G. Leff
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Inorganic Nutrients ◽  
Artificial Substrates ◽  
Response Patterns ◽  
Storm Events ◽  
Leaf Leachate ◽  
Bacterial Assemblages ◽  
The Impact ◽  
Algal Exudates

ABSTRACT Dissolved organic matter (DOM) and inorganic nutrients may affect microbial communities in streams, but little is known about the impact of these factors on specific taxa within bacterial assemblages in biofilms. In this study, nutrient diffusing artificial substrates were used to examine bacterial responses to DOM (i.e., glucose, leaf leachate, and algal exudates) and inorganic nutrients (nitrate and phosphate singly and in combination). Artificial substrates were deployed for five seasons, from summer 2002 to summer 2003, in a northeastern Ohio stream. Differences were observed in the responses of bacterial taxa examined to various DOM and inorganic nutrient treatments, and the response patterns varied seasonally, indicating that resources that limit the bacterial communities change over time. Overall, the greatest responses were to labile, low-molecular-weight DOM (i.e., glucose) at times when chlorophyll a concentrations were low due to scouring during significant storm events. Different types of DOM and inorganic nutrients induced various responses among bacterial taxa in the biofilms examined, and these responses would not have been apparent if they were examined at the community level or if seasonal changes were not taken into account.

Processing of humic-rich riverine dissolved organic matter by estuarine bacteria: effects of predegradation and inorganic nutrients

2014 ◽  
Vol 76 (3) ◽  
pp. 451-463 ◽  
Author(s):  
E. Asmala ◽  
R. Autio ◽  
H. Kaartokallio ◽  
C. A. Stedmon ◽  
D. N. Thomas
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Inorganic Nutrients

Characterising the sources and fate of dissolved organic matter in Shark Bay, Australia: a preliminary study using optical properties and stable carbon isotopes

2012 ◽  
Vol 63 (11) ◽  
pp. 1098 ◽  
Author(s):  
Kaelin M. Cawley ◽  
Yan Ding ◽  
James Fourqurean ◽  
Rudolf Jaffé
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Nutrient Dynamics ◽  
Stable Carbon Isotopes ◽  
Critical Role ◽  
Isotope Analysis ◽  
Isotopic Analysis ◽  
Low Latitude ◽  
Shark Bay ◽  
Freshwater Inputs

Low latitude, seagrass-dominated coastal bays, such as Shark Bay, Australia, are potential sources of chromophoric dissolved organic matter (CDOM) to coastal regions. Dissolved organic matter (DOM) is known to influence aquatic nutrient dynamics, microbial community structure, and depth of light penetration in estuarine systems. Shark Bay is a sub-tropical ecosystem with limited freshwater inputs and restricted tidal flushing. As such, much of the DOM is expected to be seagrass-derived. However, combining excitation/emission fluorescence spectroscopy and parallel factor analysis (EEM-PARFAC) with 13C stable isotope analysis of DOM, we found evidence for DOM inputs from terrestrial (riverine and possibly groundwater), autochthonous plankton, macroalgae, and seagrass sources. Isotopic analysis of 13C in DOM supports the idea that seagrass inputs contribute substantially to the DOM pool in Shark Bay, whereas, EEM-PARAFAC data suggests that much of this input is derived from decomposing seagrass detritus and to a lesser extent due to exudation during primary production. We also report increases in DOM concentrations and changes in DOM characteristics with increasing salinity in surface water samples, indicating that evaporation is an important control on DOM concentration and photo-degradation may play a critical role in transforming DOM within the system.

Photodegradation, interaction with iron oxides and bioavailability of dissolved organic matter from forested floodplain sources

2008 ◽  
Vol 59 (9) ◽  
pp. 780 ◽  
Author(s):  
Julia A. Howitt ◽  
Darren S. Baldwin ◽  
Gavin N. Rees ◽  
Barry T. Hart
Keyword(s):  
Organic Matter ◽  
Iron Oxide ◽  
Dissolved Organic Matter ◽  
Iron Oxides ◽  
Photochemical Reactions ◽  
Oxbow Lake ◽  
Photochemical Degradation ◽  
Fluorescence Excitation ◽  
Amorphous Iron ◽  
Leaf Leachate

Photochemical degradation of dissolved organic matter (DOM) can influence food webs by altering the availability of carbon to microbial communities, and may be particularly important following periods of high DOM input (e.g. flooding of forested floodplains). Iron oxides can facilitate these reactions, but their influence on subsequent organic products is poorly understood. Degradation experiments with billabong (= oxbow lake) water and river red gum (Eucalyptus camaldulensis) leaf leachate were conducted to assess the importance of these reactions in floodplain systems. Photochemical degradation of DOM in sunlight-irradiated quartz tubes (with and without amorphous iron oxide) was studied using gas chromatography and UV-visible spectroscopy. Photochemical reactions generated gaseous products and small organic acids. Bioavailability of billabong DOM increased following irradiation, whereas that of leaf leachate was not significantly altered. Fluorescence excitation-emission spectra suggested that the humic component of billabong organic matter was particularly susceptible to degradation, and the source of DOM influenced the changes observed. The addition of amorphous iron oxide increased rates of photochemical degradation of leachate and billabong DOM. The importance of photochemical reactions to aquatic systems will depend on the source of the DOM and its starting bioavailability, whereas inputs of freshly formed iron oxides will accelerate the processes.

Positive and negative effects of allochthonous dissolved organic matter and inorganic nutrients on phytoplankton growth

2002 ◽  
Vol 59 (1) ◽  
pp. 85-95 ◽  
Author(s):  
Jennifer L Klug
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Phytoplankton Community ◽  
Phytoplankton Growth ◽  
Inorganic Nutrients ◽  
Physiological Status ◽  
Negative Effects ◽  
Positive Effects ◽  
Negative Effect ◽  
Positive Effect

Dissolved organic matter (DOM) can have both positive and negative effects on phytoplankton growth. The magnitude of these effects may vary depending on the source of DOM and the composition of the phytoplankton community. Here, I address the relative importance of the positive and negative effects of DOM extracts on phytoplankton growth. In short-term experiments with phytoplankton from West Long Lake, a small, moderately coloured lake in northern Michigan, U.S.A., the net effect of doubling ambient DOM on phytoplankton growth was positive. Increasing DOM concentrations from ~10 mg C·L–1 to ~20 mg C·L–1 had a negative effect on total phytoplankton growth by reducing irradiance and thus reducing the depth to which growth was positive. However, inorganic nutrients in the DOM extracts increased growth at each irradiance level. The positive effect on phytoplankton growth owing to the nutrients associated with DOM was greater than the negative effect caused by shading. Although the positive effects of allochthonous DOM inputs outweighed the negative effects for the nutrient-limited phytoplankton in these experiments, the net effect depends on the concentration and availability of nutrients associated with allochthonous DOM as well as the physiological status of the phytoplankton community.

scholarly journals Single-cell visualization indicates direct role of sponge host in uptake of dissolved organic matter

2019 ◽  
Vol 286 (1916) ◽  
pp. 20192153 ◽  
Author(s):  
Michelle Achlatis ◽  
Mathieu Pernice ◽  
Kathryn Green ◽  
Jasper M. de Goeij ◽  
Paul Guagliardo ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Secondary Ion Mass Spectrometry ◽  
Physiological Mechanism ◽  
Marine Sponges ◽  
Direct Role ◽  
Transmission Electron ◽  
High Enrichment ◽  
The Individual ◽  
Near Future

Marine sponges are set to become more abundant in many near-future oligotrophic environments, where they play crucial roles in nutrient cycling. Of high importance is their mass turnover of dissolved organic matter (DOM), a heterogeneous mixture that constitutes the largest fraction of organic matter in the ocean and is recycled primarily by bacterial mediation. Little is known, however, about the mechanism that enables sponges to incorporate large quantities of DOM in their nutrition, unlike most other invertebrates. Here, we examine the cellular capacity for direct processing of DOM, and the fate of the processed matter, inside a dinoflagellate-hosting bioeroding sponge that is prominent on Indo-Pacific coral reefs. Integrating transmission electron microscopy with nanoscale secondary ion mass spectrometry, we track 15 N- and 13 C-enriched DOM over time at the individual cell level of an intact sponge holobiont. We show initial high enrichment in the filter-feeding cells of the sponge, providing visual evidence of their capacity to process DOM through pinocytosis without mediation of resident bacteria. Subsequent enrichment of the endosymbiotic dinoflagellates also suggests sharing of host nitrogenous wastes. Our results shed light on the physiological mechanism behind the ecologically important ability of sponges to cycle DOM via the recently described sponge loop.

scholarly journals Behaviour of dissolved organic matter and inorganic nutrients during experimental sea-ice formation

2001 ◽  
Vol 33 ◽  
pp. 317-321 ◽  
Author(s):  
Virginia Giannelli ◽  
David N. Thomas ◽  
Christian Haas ◽  
Gerhard Kattner ◽  
Hilary Kennedy ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Sea Ice ◽  
Organic Compounds ◽  
Sea Water ◽  
Ice Cores ◽  
Inorganic Nutrients ◽  
Ice Formation ◽  
Solid Matrix ◽  
Dissolved Organic Compounds

AbstractIt is well established that during sea-ice formation, crystals aggregate into a solid matrix, and dissolved sea-water constituents, including inorganic nutrients, are rejected from the ice matrix. However, the behaviour of dissolved organic matter (DOM) during ice formation and growth has not been studied to date. DOM is the primary energetic substrate for microbial heterotrophic activity in sea water and sea ice, and therefore it is at the base of the trophic fluxes within the microbial food web. The aim of our study was to compare the behaviour of DOM and inorganic nutrients during formation and growth of sea ice. Experiments were conducted in a large indoor ice-tank facility (Hamburg Ship Model Basin, Germany) at −15°C. Three 1 m3 tanks, to which synthetic sea water, nutrients and dissolved organic compounds (diatom-extracted DOM) had been added, were sampled over a period of 5 days during sea-ice formation. Samples were collected throughout the experiment from water underlying the ice, and at the end from the ice as well. Brine was obtained from the ice by centrifuging ice cores. Inorganic nutrients (nitrate and phosphate) were substantially enriched in brine in comparison to water and ice phases, consistent with the processes of ice formation and brine rejection. Dissolved organic carbon (DOC) was also enriched in brine but was more variable and enriched in comparison to a dilution line. No difference in bacteria numbers was observed between water, ice and brine. No bacteria growth was measured, and this therefore had no influence on the measurable DOC levels. We conclude that the incorporation of dissolved organic compounds in newly forming ice is conservative. However, since the proportions of DOC in the brine were partially higher than those of the inorganic nutrients, concentrating effects of DOC in brine might be different compared to salts.

scholarly journals Sensitivity of the N. AEGEAN SEA ecosystem to Black Sea Water inputs

2014 ◽  
Vol 15 (4) ◽  
pp. 790 ◽  
Author(s):  
G. PETIHAKIS ◽  
K. TSIARAS ◽  
G. TRIANTAFYLLOU ◽  
S. KALARONI ◽  
A. POLLANI
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Black Sea ◽  
Sea Water ◽  
Aegean Sea ◽  
Microbial Loop ◽  
Inorganic Nutrients ◽  
The North ◽  
North Aegean Sea ◽  
The Impact

The effect of Black Sea Water (BSW) inputs on the North Aegean Sea productivity and food web dynamics was investigated, by means of sensitivity simulations, investigating the effect of the inflowing BSW, in terms of inorganic nutrients and dissolved organic matter. The model used has been successfully applied in the area in the past and extensively presented. Considering the importance of the microbial loop in the ecosystem functioning, the role of the dissolved organics and in order to achieve a more realistic representation of the Dissolved Organic Matter pool, the bacteria sub-model was appropriately revised. The importance of the microbial loop is highlighted by the carbon fluxes where almost 50% of carbon is channelled within it. The impact of dissolved organic matter (DOM) (in the inflowing to the Aegean Sea, BSW) appears to be stronger than the impact of dissolved inorganic nutrients, showing a more extended effect over the N Aegean. Bacterial production and biomass is more strongly affected in the simulations by modified DOM, unlike phytoplankton biomass and production, which are more dependent on the inflowing nutrients and particularly phosphorus (inorganic and dissolved organic). In the phytoplankton composition, the dinoflagellates appear to be mostly affected, being favoured by higher nutrient availability at the expense of all other groups, particularly picoplankton, indicating a shift to a more classical food chain.

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